MACOMB COUNTY, Mich. – Repairs have been made to a major Macomb County sanitary sewer to prevent a concrete pipe from collapsing and creating a sinkhole, officials said.
Macomb County Public Works Commissioner Candice S. Miller said an inspection of a 7-foot diameter sewer in 2022 found severe degradation of the concrete pipe. The damage was caused by corrosive hydrogen sulfide gas that is created by turbulence of raw sewage.
Crews installed something known as a “spiral wound pipe” (SPR), which lines the interior of a 755-foot section of the Garfield Interceptor Sewer beneath Garfield Road at 21 Mile Road in Macomb Township.
“I’m not exaggerating when I say that with the condition of this interceptor right here at 21 Mile and Garfield, if we weren’t taking these steps, we could have a sinkhole here,” Miller said.
What is a spiral wound pipe?
SPR is a method of sewer construction that requires little or no digging and can be installed when sewage is flowing through the pipe.
It involves inserting a flexible liner strip inside the current pipe and then sealing the edges of the strip together to form a liner inside the pipe.
According to officials, this is the first time the SPR has been used in Michigan to rehabilitate a sewer. The SPR is expected to last at least 50 years.
Installation was finished in late March. The next step in the process is grouting, which is already underway. That step is expected to take four weeks to complete.
The rehabilitation project cost $3 million and will not require a sewer rate increase, according to officials.
The closure of one lane of Garfield Road is expected to be lifted by the end of May.